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Extension Entomology

Category: Lawn and Garden

Army Cutworm Moths Still Flying in Southwest Kansas

Posted on by Sharon Schroll

–by Anthony Zukoff – Entomology Southwest Research and Extension Center
Garden City, KS

Noticeable numbers of army cutworm moths, also called Miller moths, have been observed in a couple locations in western Kansas this year.  Army cutworms are late fall and early spring pests of several Kansas crops, especially wheat.  These moths begin migrating into Kansas and neighboring states in the fall from their over-summering locations in the Rocky Mountains.  This year, moths began showing up in western Kansas during the first week of September.  In the last six weeks, over 1600 moths have been collected in pheromone traps at a location in Finney County.  Trap counts of 800 or more moths in an area may indicate increased caterpillar activity the following spring.  Right now, females will be laying eggs on the soil surface of freshly cultivated, weedy or newly seeded winter wheat fields.  Each female can lay up to 1000 eggs or more.  After hatching, caterpillars will begin feeding and do so until cold weather forces them below ground.  However, it is possible for them to resume feeding on warmer winter days.  Caterpillars will complete their growth next spring and then burrow into the soil to pupate. Sexually immature adults emerge in late spring and migrate back to the mountains for summer.  Fields should be scouted during warm periods between February and April.  Fields under stressful conditions, such as the current drought, may suffer economic damage with only 1-2 caterpillars per square foot. Typically, treatment will not be necessary until populations average 4-5 per square foot and well-tillered fields under good growing conditions can tolerate up to 10 per square foot without measurable yield loss. More information regarding control options for this pest in wheat and other crops can be found in the KSRE Insect Management Guides.

Army cutworm moths in a pheromone trap in Finney County

 

 

 

 

Goldenrod Soldier Beetles

Posted on by Sharon Schroll

–by Raymond Cloyd — Horticultural Entomologist

Goldenrod soldier beetle, Chauliognathus pennsylvanicus, adults are feeding on goldenrod (Solidago spp.) (Figure 1) as well as other flowering plants. Adults can be seen feeding and mating simultaneously. The goldenrod soldier beetle is common throughout most of Kansas.

Figure 1. Goldenrod soldier beetle adults feeding goldenrod flowers (Raymond Cloyd, KSU)

Adults are about 1/2 of an inch long, elongated, and orange with two dark bands on the base of the forewings (elytra) and thorax (middle section) (Figure 2). In general, adults are present from August through September. Adult soldier beetles feed on the pollen and nectar of flowers. In addition, they are predators and will consume insects such as aphids and caterpillars. Flowers are a great place for the male and female soldier beetle adults to meet and then mate (Figure 3). Soldier beetle adults do not cause plant damage. Adults may occasionally enter homes, but they are rarely a concern. The best way to deal with adults in the home is to sweep, hand-pick, or vacuum.

Figure 2. Goldenrod soldier beetle adult (Raymond Cloyd, KSU)

Figure 3. Goldenrod soldier beetle adults mating (Raymond Cloyd, KSU)

 

Adult females lay clusters of eggs in the soil. The larva that emerges (eclose) from eggs are dark-colored, slender, and covered with small dense hairs or bristles, which gives the larva a velvety appearance. The larva resides in soil feeding on grasshopper eggs. Sometimes, the larva will emerge from the soil and feed on soft-bodied insects and small caterpillars.

 

Elm Leaf Beetle

Posted on by Sharon Schroll

–by Raymond Cloyd, Horticultural Entomology

Elm leaf beetle, Pyrrhalta luteola, larvae and adults are prevalent throughout Kansas feeding on elm trees (e.g. Siberian and American). The larvae and adults are typically present simultaneously. Extensive feeding damage can ruin the aesthetic quality of elms in landscapes, parks, and other areas where elms are grown.

Elm leaf beetle adults are 1/5 to 1/4 of an inch long, yellow to dull-green, with a black stripe on each side of the wing cover that extends the entire length of the abdomen (last section). In addition, there are two black spots on both sides of the thorax (middle section) (Figure 1). Adults feed between the major veins, which results in leaves having a ‘shot hole’ (similar to ‘buckshot’) appearance (Figure 2).

Figure 1. Elm leaf beetle adult (Raymond Cloyd, KSU)

 

Figure 2. Feeding damage associated with elm leaf beetle adults (Raymond Cloyd, KSU)

Elm leaf beetle larvae are 1/3 to 1/2 of an inch long when mature and dull-yellow with two black lines extending the length of the body (Figure 3). The larvae cause the most damage feeding for about three weeks. The larvae feed on the underside of leaves causing the leaves to appear skeletonized and eventually turning brown (Figure 4). The larvae will migrate down the trunk of elm trees and tunnel into or reside on the soil surface to pupate (Figure 5). Adults emerge later on and migrate upward on the tree trunk. In late summer through fall, elm leaf beetle adults will leave elm trees and seek sites to overwinter. Adults overwinter in buildings, homes, and in protected places outdoors such as the bark of elm trees. Adults can be a nuisance pest inside homes when they enter in the fall or leave in the spring. There are two generations per year in Kansas.

Figure 3. Elm leaf beetle larvae feeding on leaf underside (Raymond Cloyd, KSU)

 

Figure 4. Feeding damage associated with elm leaf beetle larvae (Raymond Cloyd, KSU)

Figure 5. Elm leaf beetle larvae and pupae on the soil surface at the base of an elm tree (Raymond Cloyd, KSU)

A contact insecticide should be applied in spring to manage elm leaf beetle larvae and adult populations feeding on leaves. Thorough coverage of leaf undersides is important because the leaf undersides are where larvae and adults primarily feed. However, if elm trees are exhibiting ≥50% feeding damage then do not spray. Mature elm trees can usually sustain damage associated with elm leaf beetle larvae and adults feeding without direct harm. However, be sure to implement cultural practices such as providing sufficient water and mulching the base of elm trees to ensure that elm trees produce leaves for next year.

Systemic insecticides can be applied to the soil or injected directly into elm trees in early spring before new growth emerges. The systemic insecticide active ingredient will translocate throughout the elm tree and accumulate in the leaves. Elm leaf beetle larvae and adults are killed when they ingest a lethal concentration of the systemic insecticide active ingredient after feeding on leaves.

 

For more information on how to manage elm leaf beetle populations please refer to the following extension publication:

 

Elm Leaf Beetle: Insect Pest of Elm Trees (MF3537 July 2020)

https://www.bookstore.ksre.ksu.edu/pubs/MF3537.pdf

 

Blister Beetles

Posted on by Sharon Schroll

— by Raymond Cloyd — Horticultural Entomologist

 

If you are growing Swiss chard, Beta vulgaris subsp. vulgaris, in your vegetable garden, you may be encountering leaf feeding damage caused by the adult stage of two blister beetle species: the ashgray blister beetle, Epicauta fabricii (Figure 1),

Figure 1. Ashgray blister beetle adult (Raymond Cloyd, KSU)

and the threestriped blister beetle, Epicauta lemniscata (Figure 2).

 

Figure 2. Threestriped blister beetle adult (Raymond Cloyd, KSU)

Both can cause extensive plant damage (Figure 3) and leave black fecal deposits (“poop”) on plant leaves (Figure 4).

Figure 3. Extensive plant damage to Swiss chard caused by adult blister beetle feeding (Raymond Cloyd, KSU

Figure 4. Fecal deposits (poop) associated with blister beetle adult feeding (Raymond Cloyd, KSU)

The best way to deal with these insect pests is to remove the adults by hand and place into a container of soapy water. Be sure to wear gloves when handling blister beetle adults because they can emit a substance called cantharadin that may cause blisters when in contact with the skin.

 

Gorgone Checkerspot

Posted on by Sharon Schroll

–by Raymond Cloyd – Horticultural Entomologist

 

Have you noticed the leaves on your sunflower, Helianthus annuus, plant being fed upon by caterpillars (Figure 1)?

Figure 1. Gorgone checkerspot caterpillars on leaf of sunflower (Raymond Cloyd, KSU)

If so, the caterpillar is the gorgone checkerspot, Chlosyne gorgone. The caterpillar ranges in color from black to orange, with a black head and spines or barbs covering the body (Figures 2 and 3).

Figure 2. Gorgone checkerspot caterpillars (Raymond Cloyd, KSU)

Figure 3. Gorgone caterpillar (Raymond Cloyd, KSU)

The caterpillars feed on sunflowers and other related plants. The caterpillars initially feed in groups (Figure 4)

Figure 4. Gorgone caterpillars feeding on sunflower leaf (Raymond Cloyd, KSU)

whereas later on the mature caterpillars, which are approximately 1.0 inch in length, feed individually (Figure 5). Third instar larvae eventually searches for a place to overwinter.

Figure 5. Mature gorgone caterpillar (Raymond Cloyd, KSU)

If you see caterpillars feeding on sunflower leaves and your plants can tolerate some feeding damage, then just leave them alone as the caterpillars will eventually develop, by means of complete metamorphosis, into beautiful butterflies.

 

Mimosa Webworm

Posted on by Sharon Schroll

–by Raymond Cloyd – Horticultural Entomologist

 

Damage caused by mimosa webworm, Homadaula anisocentra, larvae/caterpillars is prevalent on honey locust, Gleditsia triacanthos, and mimosa, Albizia julibrissin, trees throughout most regions of Kansas. The larvae/caterpillars are 1/2 of an inch long when full-grown (Figure 1)

Figure 1. Mimosa webworm caterpillars feeding on leaves (Raymond Cloyd, KSU)

and rapidly move backward when disturbed. Caterpillars’ web leaves together on the ends of branches (Figure 2).

Figure 2. Mimosa webworm webbing on end of branch (Raymond Cloyd, KSU)

Webbing typically starts at the tops of trees and protects caterpillars from natural enemies (parasitoids and predators) and insecticide spray applications. Heavily-infested trees are brown or scorched in appearance (Figures 3 through 5) as the caterpillars skeletonize the leaf tissue. Caterpillars eventually fall from trees on a silken strand before pupating. Mimosa webworm pupates in bark crevices or pupae are attached to structures (e.g. buildings). There are two generations per year in Kansas.

Figure 3. Mimosa webworm caterpillar feeding damage (Raymond Cloyd, KSU)

Figure 4. Extensive feeding damage caused by mimosa webworm caterpillars (Raymond Cloyd, KSU)

Figure 5. Extensive feeding damage caused by mimosa webworm caterpillars (Raymond Cloyd, KSU)

At this time of year it is too late to apply an insecticide when trees are already heavily infested with webbing because caterpillars are protected from insecticide spray applications inside the leaf webbing. However, next year, you can manage mimosa webworm caterpillar populations by applying an insecticide when the caterpillars are initially present and exposed to insecticide spray applications. You can use insecticides that contain the following active ingredients: Bacillus thuringiensis subsp. kurstaki, spinosad, bifenthrin, cyfluthrin, and permethrin. Read the label of each product to ensure that “webworms” are listed. High-volume spray applications are required to contact the caterpillars. If possible, selective pruning can quickly remove isolated or localized infestations of mimosa webworm.

Cicada Killer

Posted on by Sharon Schroll

–by Raymond Cloyd — Horticultural Entomologist

We are receiving inquiries regarding large wasps flying around in landscapes and gardens. These large wasps are the Eastern cicada killer, Sphecius speciosus. Cicada killer adults are approximately 2.0 inches long and black with yellow-banded markings on the abdomen. The head and transparent wings are red-brown (Figure 1). Cicada killers are not dangerous, but they are intimidating; especially the males. Cicada killers are solitary wasps, not social wasps like yellowjackets. Adults live up to 75 days from July through September, and feed on flower nectar and plant fluids.

Figure 1. Cicada Killer Adult (Raymond Cloyd, KSU)

A female cicada killer will dig a 6 to 10-inch burrow (1/2 inch in diameter) in the soil; usually in sandy or loose soil. A pile of sand or soil, depending on soil type, will surround the entrance. Afterwards, cicada killer females search for dog days cicada, Tibicen pruinosa, adults located on the trunks and lower branches of trees. The female stings an adult cicada using her ovipositor (egg-laying device), flips the cicada over, straddles the cicada, and then transports the immobilized or paralyzed cicada back to the burrow in the soil (Figures 2 and 3). Each burrow may contain three to four cells with one or two cicadas. The dead cicada serves as a food source for the cicada killer larvae, which are legless and grub-like. A female will lay one egg per cicada if the egg is unfertilized. Larvae that emerge from unfertilized eggs are males whereas larvae that emerge from fertilized eggs are females and are provided with two cicadas. Larvae emerge (eclose) from eggs in two to three days and feed on paralyzed cicadas. The female will eventually cover the burrow, dig another one, and repeat the process. Full-grown larvae overwinter inside silken cases, pupate in spring, and adults emerge from July through August. There is one generation per year in Kansas.

Figure 2. Cicada Killer Female Transporting A Paralyzed Cicada To Her Nest (Raymond Cloyd, KSU)

 

Figure 3. Cicada Killer Adult Female With Dead Cicada

Cicada killers are an urban nuisance pest, especially when large numbers are nesting in bare areas, in turfgrass, or around a structure. People are generally concerned because cicada killers resemble giant yellowjackets or they think cicada killers are the so-called “Murder Hornet”. However, in general, cicada killers will not sting an individual. Wasp and bee female stingers are modified egg-laying devices (ovipositors), so males cannot sting. Females may sting if they going to be stepped on with bare feet or grabbed with bare hands.

Male cicada killers establish aerial territories and patrol for intruders. A male cicada killer wards-off other males that enter his territory and attempt to mate with females. An individual that walks into the territory is typically confronted by a very large wasp hovering in front of the face that ‘zips’ to the side and back. However, after determining that the intruder is not a rival or a threat, the male cicada killer ignores the individual. Nonetheless, an individual walking across a lawn, fairway, or other area where cicada killers are nesting, will experience the same treatment through each male’s territory. Sometimes there can be up to 20 cicada killer males in one area. After females have departed the nest, then males will eventually leave.

Cicada killers are common in areas with bare soil, so mulching, planting ground covers, or sodding may reduce potential problems with cicada killer populations. Cicada killers can be a problem in well-maintained areas such as irrigated and regularly fertilized turfgrass. In addition, cicada killers can be a problem when nesting in areas accessible to or frequented by the public. Applying carbaryl or pyrethroid-based insecticides containing the active ingredients; permethrin, bifenthrin, cyfluthrin, and/or lambda-cyhalothrin to the burrowed (nesting) area may kill females in golf course sand traps. In home yards, cover sandboxes with a tarp when not in use to deter cicada killers. Sand below swings, jungle gyms, or other playground equipment should be replaced with bark mulch or shredded tires.

Managing cicada killers in baseball infields and volleyball courts is more difficult because people with minimal clothing and exposed skin are diving and sliding onto the soil. Consequently, the use of an insecticide may not be an option. However, in the case of a volleyball court, a geotextile fabric placed beneath the sand may create a barrier that prevents cicada killers from creating burrows.

 

 

Green June Beetle Adult

Posted on by Sharon Schroll

–by Raymond Cloyd — Horticultural Entomologist

 

Green June beetle, Cotinis nitida, adults are flying around in massive numbers over both managed and unmanaged grassy areas. Green June beetle adults are erratic flyers and occasionally bump into people and objects. Adults are 3/4 to 1.0 inch long, velvety-green, with yellow-orange margins extend lengthwise on the front wings (Figure 1). The underside of the body is shiny and metallic green or gold. Adults fly around for several weeks from July through August. Green June beetle adults are sometimes mistaken for Japanese beetle, Popilla japonica, adults; however, they really do not look alike.

Figure 1. Green June Beetle Adult (Raymond Cloyd, KSU)

Green June beetle has a one-year life cycle, overwintering as a mature larva or grub in the soil. Adults typically emerge from late-June through early-July and are active during the day, resting at night on plants, in thatch, or in compost. Adults produce a sound when flying that is similar to bumble bees. Adults feed on ripening fruits and corn tassels, and may feed on the leaves of oak and maple trees. Male green June beetles swarm in the morning, flying to-and-fro just above managed and/or unmanaged grassy areas where females are located. The females emit an odor or pheromone that attracts the males. Clusters of beetles may be seen on the soil surface or in grassy areas with several males attempting to mate with a single female. After mating, females lay clusters of 10 to 30 eggs in moist soil with a high organic matter content. The larvae emerge (eclose) from eggs in approximately two weeks and feed near the soil surface. Larvae are 3/8 of an inch (early instars) to 1-1/2 (later instars) long and have the distinct characteristic of crawling on their back (Figure 2). Larvae primarily feed on organic matter in thatch or grass-clippings.

 

Figure 2. Green June Beetle Larva Crawling On Back (Raymond Cloyd, KSU)

 

For more information on how to manage green June beetle adults and larvae refer to the following extension publication:

 

Green June Beetle: Insect Pest of Turfgrass (MF3600 March 2022)

https://www.bookstore.ksre.ksu.edu/pubs/MF3600.pdf

Squash Bug

Posted on by Sharon Schroll

–by Raymond Cloyd – Horticultural Entomology

 

Squash bug, Anasa tristis, females have laid eggs and various stages of the nymphs are present feeding on squash and pumpkin leaves. Squash bug adults are flattened and 1/2 to 3/4 of an inch in length. Adults are dark-brown and have wings with brown-to-black and orange markings along the outer edge of the body (Figure 1). Females lay red-orange eggs on the leaf underside and top of leaves. Nymphs emerge (eclose) from the eggs in seven to 14 days and undergo five instars (stages between each molt) before maturing to adults. First instar nymphs that emerge from eggs have a red head and thorax (middle section) and pale-green abdomen (Figure 2). Second instar nymphs have a black head and thorax and a pale-green abdomen (Figure 3).

Figure 1. Squash bug adult (Raymond Cloyd, KSU)

Figure 2. Young squash bug nymphs (Raymond Cloyd, KSU)

Figure 3. Young squash bug nymphs (Raymond Cloyd, KSU)

Nymphs tend to gather near the eggs after emerging. Older nymphs (3rd to 5th instar) are gray (Figure 4) and tend to distribute themselves over the entire plant (Figure 5). Nymphs are 3/16 of an inch long and cannot fly because they do not have fully-developed wings.

Squash bug nymphs and adults use their piercing-sucking mouthparts to withdraw plant fluids from leaves, stems, vines, and fruits. Damage to leaves appears as small, yellow specks that eventually turn brown (Figure 6).

Figure 4. Older squash bug nymphs (Raymond Cloyd, KSU)

Figure 5. Older squash bug nymphs on the stem (Raymond Cloyd, KSU)

Figure 6. Feeding damage caused by squash bug (Raymond Cloyd, KSU)

Below are the plant protection strategies that you can implement to mitigate problems with squash bugs and prevent subsequent plant damage.

  1. Check plants for the presence of eggs, nymphs, and adults on leaf undersides at least once per week during the growing season.
  2. Destroy eggs, and remove (handpick) nymphs and adults, placing them into a container with soapy water to kill them. Handpick every three to four days.
  3. Place a floating row cover over plants to protect them from squash bug nymphs and adults.
  4. Position wooden boards throughout the garden, turning them over daily to collect squash bugs hiding underneath. You can kill the squash bugs by placing into a container of soapy water.
  5. Apply a contact insecticide when the nymphs are present. The smaller nymphs are easier to kill than the larger nymphs. Contact insecticides are less effective against adult squash bugs because adults have a thickened waxy cuticle (skin) that insecticides cannot adhere to and penetrate. Adults are also protected from insecticide sprays by the leafy plant canopy. Weekly applications of contact insecticides may be required to maintain populations below levels that will prevent plant damage. Thorough coverage of the leaf undersides is important to manage squash bug populations.

 

For more information on how to manage squash bug populations refer to the following extension publication:

 

Squash Bug (MF3308 July 2016)

https://www.bookstore.ksre.ksu.edu/pubs/MF3308.pdf

 

 

Flower Wasps Getting Attention In Yards and Fields

Posted on by Sharon Schroll

–by Anthony Zukoff –Southwest Research and Extension Center – Garden City, KS

 

A wasp commonly found during the summer in Kansas has recently caused concern among home owners and producers.  In one instance, several wasps were mistaken for wheat stem sawfly, a significant pest of wheat that has not yet established in Kansas.  Sometimes referred to as flower wasps, the Five-banded Tiphiid Wasp (Myzinum quinquecinctum), is a harmless solitary wasp found throughout most of the country. 

Male Flower Wasp

 

In Kansas, it is found statewide and is most common mid to late summer.  These ¾ to 1 inch long, narrow bodied wasps have dark bodies, long antennae and smoky wings.  Yellow markings are visible on their thorax and yellow bands are present on each abdominal segment.  Subtle differences set apart males and females.  Male wasps have yellow legs, while females have stockier orange-red legs and wider yellow bands on their abdominal segments.  Both male and females visit flowers to feed on nectar.  Females are parasitoids of various scarab beetle larvae, including common turfgrass pests such as white grubs, and have been promoted as biocontrol tools in farm and turf settings.  Female wasps seek out beetle larvae in the ground, digging for them with their stocky legs. She then deposits an egg on the body of the grub and injects a neurotoxin to paralyze it. As the wasp larva develops it will consume the beetle larva.  The wasp then overwinters as a pupa below the ground and emerges as an adult the following summer.  Since the populations of both the wasp and its host fluctuate yearly, the level of parasitism changes from season to season.  This results in some years where many wasps successfully overwinter and emerge in large numbers.

Male Wasps on Corn

The female wasps are not commonly encountered.  In fact, it is the male of this species that most often causes alarm.  This is due to the fact that the males tend to congregate together in large numbers on vegetation and occasionally even on home siding.  These groups are typically attracted to an area because there are nectar sources, shade or tall grass to shelter on over the evening.  When approached or disturbed, the group of male wasps take flight and fly circles around the location, giving the appearance of an angry swarm of wasps.  The males have no stinger and are harmless, however, the hooked appendage at the end of their abdomen is often mistaken for a stinger, adding to the alarm.  Despite their behavior and large numbers, these wasps are no threat to people, pets or landscaping. As summer progresses, these groups of male flower wasps will slowly die off and eventually disappear.